Change in flashrom[master]: buspirate_spi: Tristate IOs when using using pullup=on

[Nico Huber (Code Review)]

Nico Huber has submitted this change and it was merged. ( https://review.coreboot.org/23864 )

Change subject: buspirate_spi: Tristate IOs when using using pullup=on
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buspirate_spi: Tristate IOs when using using pullup=on

Avoid putting 3.3V on IO pins when pullup=on to avoid damage to 1.8V
chips.

Signed-off-by: David Hendricks 
Change-Id: I9ac4c6b7a0079bb1022f2d70030a6eb29996108f
Reviewed-on: https://review.coreboot.org/23864
Tested-by: build bot (Jenkins) 
---
M buspirate_spi.c
1 file changed, 4 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  David Hendricks: Looks good to me, approved

diff --git a/buspirate_spi.c b/buspirate_spi.c
index db8b310..fad309f 100644
--- a/buspirate_spi.c
+++ b/buspirate_spi.c
@@ -543,6 +543,10 @@

/* Set SPI config: output type, idle, clock edge, sample */
    bp_commbuf[0] = 0x80 | 0xa;
+	if (pullup == 1) {
+		bp_commbuf[0] &= ~(1 << 3);
+		msg_pdbg("Pull-ups enabled, so using HiZ pin output! (Open-Drain mode)\n");
+	}
    ret = buspirate_sendrecv(bp_commbuf, 1, 1);
    if (ret)
    	return 1;